The utilisation of horological or scientific apparatuses, at night or in poor visibility, has always been inconvenient. In horology, the need to tell the time in the dark has, in the past, given rise to tact watches, and also to watches that strike on demand, whose cost prevented widespread use. The use of radioactive paints, particularly radium-based paints, has made night reading easier, but at the cost of the user's health, and with a conspicuous appearance, day and night, which is often not appreciated by the user. The miniaturisation of electrical energy sources then made it possible to incorporate electrical lighting devices, but with the constraint that the cells or batteries frequently require changing. There are capacitor or battery charger mechanisms using the motions of certain watch components, such as the oscillating weight, but they are expensive and occupy internal space.
US Patent Application No 2005/018545A1, in the name of SEYR ERNEST (ETERNA), discloses a watch display device with a luminescent surface for backlighting a display element (alphanumerical symbols). These symbols may be mounted in an aperture in an opaque dial, the luminescent surface covers at least a partial section of a support surface arranged behind the aperture, the alphanumerical symbols of the display element include an opaque material, and the alphanumerical symbols of the display element are arranged between the dial and the luminescent surface.
U.S. Pat. No. 3,851,460A in the name of PIQUEREZ discloses a watch with a glass comprising a metallized groove filled with a luminescent material which reflects the light from the luminescent material towards the watch dial.
US Patent Application No 2011/164475 A1 in the name of JAN WENZEL (LANGE UHREN) discloses a watch with a pot-shaped case, comprising an opening oriented towards a user, with a movement and components comprising upper light-receiving surfaces arranged in the case and revealed by an open part allowing light to pass through from the user's side, the light from the exterior reaching said light-receiving surfaces through said open part, the open part is transparent to ultra violet rays, and is opaque at least to the visible light spectrum.
WO Patent Application No 2005/045533A1 in the name of LANGE UHREN discloses a watch display. A luminescent material is applied to the display discs, on which display symbols are printed, or which surrounds pre-printed symbols, so as to form a luminescent surface which makes the symbols visible in the dark or in low lighting.
FR Patent Application No 2011614A1 in the name of HAMILTON MATCH CY discloses a watch with luminous information means, visible through an aperture, and comprising an optical fibre beam. The watch case may carry a lighting source, which may be a radioactive source.